It was narrated that 'Abdullah bin 'Amr said:
"It was said to the Messenger of Allah (peace be upon him): 'Which of the people is best?' He said: 'Everyone who is pure of heart and sincere in speech.' They said: 'Sincere in speech, we know what this is, but what is pure of heart?' He said: 'It is (the heart) that is pious and pure, with no sin, injustice, rancor or envy in it.'"
Sunan Ibn Majah , Vol. 5, Book 37, Hadith 4216.